In particular in safety-critical systems, that is to say systems in which the emphasis is on functional and operational safety, protection of the equipment integrity or system integrity, i.e. the invariability of the installed software or firmware, is an important factor. Ensuring the protection of the equipment integrity or even of the configuration parameters supports here the integrity of computation results (data) and therefore the functionality of the equipment.
WO 2012/135192 A2 discloses, for example, monitoring by means of a virtual machine monitor (VMM) whether the communication with a virtual machine potentially contains damaging code.
Generally, virus scanners are known which serve to detect damaging functions such as computer viruses or Trojan horses. Furthermore, intrusion detection systems are known which are intended to detect intrusions directed at a computer system or computer network (see also http://de.wikipedia.org/wiki/Intrusion Detection System).
DE 10 2006 036 111 B3 discloses a method and checking system for reliably transmitting a message from a first zone into a second zone. In this context, the message is transmitted from the first zone to an evaluation unit of a third zone by means of a data diode. Copies of the message are made available here to various analysis units which check this message and, where appropriate, pass it on into a second zone as a function of the evaluation result of all the analysis units. After successful analysis has taken place, an analysis unit can be reset in order to avoid possibly being adversely affected by malware.
Furthermore, what is referred to as a “Secure Boot” is known (see http://www.webopedia.com/TERM/M/microsoft_secure_boot.html). In this context, a secure boot functionality is made available during the starting or booting, in order to prevent malware from being started during the booting process of the system.
A runtime integrity check (see http://www. intl.com/content/dam/doc/white-paper/intl-it-security-trusted-execution-technology-paper.pdf) is also known. In this context, checking for malware or manipulation is also carried out during the starting of a system or an application.